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Biomedical subjects

K Wester

Publications and source records attributed to K Wester.

At least 19 recordsLinked to original sources
PubMed1992

[Organ donation from recently deceased patients. Experiences from a donor hospital and suggestions for handling potential organ donors and their relatives].

Homologous organ transplantation using organs from patients suffering complete destruction of the brain and brain stem is a major achievement in modern medicine. The care of potential organ donors and their relatives is complex and very demanding for the medical team and nursing staff. In Norway the law sets very clear criteria (documentation of total irreversible brain and brain stem injury) for performing donation. As a rule consent from the family is asked for, although not legally required. This article deals with the problems related to the treatment of potential organ donors. We give practical guidelines for medical staff on how to prepare the patient and his/her family, with emphasis on the human and psychosocial aspects. Preservation of the donor and the organs is not discussed.

Decision Making↗
PubMed1992

Combined intra-arterial chemotherapy followed by radiation in astrocytomas.

Seventy-five patients harboring astrocytomas received 4 cycles of infra-ophthalmic carotid injections of BCNU, combined with vincristine intravenously and procarbazine orally. All of the patients thereafter, received radiation therapy. The five year survival was 73% for all patients. The age of the patients had no significant impact on survival. The treatment results were compared with the results of 57 patients with astrocytomas who were treated with surgery followed by radiation in the same period. These 57 patients had a 5 year survival of 45% with a five year survival in patients < or = 40 years and patients > 40 years of 70% and 22%, respectively (p < 0.05). In multivariate survival analysis of the BCNU group and radiation group together, treatment group and corticosteroid dependency were the only prognostic factors. No leukoencephalopathy was seen during the treatment or in the follow-up of the patients. We conclude that pre-radiation intra-arterial chemotherapy can be given without significant morbidity and produces an improvement in survival in patients older than 40 years.

Administration, Oral↗
PubMed1992

The prognostic value of intra-operative observations during thalamotomy for parkinsonian tremor.

Data from 27 thalamotomies were analyzed with respect to possible correlations between certain intra-operative observations and the long-term effect on parkinsonian tremor. Tremor reduction caused by mechanical impact of the electrodes in the target area was not correlated with the long-term effect on the tremor. The same was true for the threshold intensities during the intra-operative electrical stimulation of the target area, stimulation that facilitates and/or inhibits the tremor. In a minority of the patients, all with good long-term results, a combination of a pronounced tremor inhibition from the electrode insertion and a low threshold intensity was observed. Variations in other lesion parameters were not correlated with the outcome. The results are discussed within the framework of a "tremor" vs. a "tonus" mechanism underlying the thalamotomy effect.

Aged↗
PubMed1992

Dysfunction of Holter Mini Elliptical valves caused by minor head trauma.

Two patients with implanted shunts suffered three disconnections of the shunt catheters from the valve chamber as a result of minor head trauma. In all instances a Holter Mini Elliptical valve had been used. The design of this valve may facilitate the kind of shunt dysfunction described. Suggestions are made for small changes in the shunt design or surgical procedures to obviate the vulnerability of the shunt to minor trauma.

Astrocytoma↗
PubMed1992

Expression of proliferative cell nuclear antigen (PCNA) in urinary bladder carcinoma. Evaluation of antigen retrieval methods.

Proliferative cell nuclear antigen (PCNA) expression was analyzed in formalin-fixed and paraffin-embedded specimens from patients with urinary bladder cancer using three different anti-PCNA monoclonal antibodies. In 20 recent cases a positive correlation was found between the extent and intensity of PCNA staining and grade of malignancy. In 95 specimens, three to six years old, extensive positive staining was detected in 15 and 23% of grade 2B and 3-4 tumors, respectively. No equivalent staining was found in the grade 1 and 2A tumors. In material more than six years old, a remarkably weak staining was observed regardless of grade. Similarly, in a test of archival material of tonsils a very weak immuno-reactivity was found as compared with fresh material. However, antigen retrieval by microwave heating of the tissue sections was possible in the majority of all cases, and the difference in extent and intensity of the staining between low and high grade tumors remained.

Antibodies, Monoclonal↗
PubMed1992

Benign intracerebral cysts treated with internal shunts: review and report of two patients.

Two elderly women with symptomatic benign intracerebral cysts are reported. Before treatment, they both had developed moderate, but slowly increasing, symptoms from a cyst in the left hemisphere, which included epileptic seizures and right hemiparesis. During local anesthesia, an internal cystosubarachnoid shunt was inserted. After the operation, the cyst size was reduced markedly, with a corresponding improvement in the symptoms. A review of reported cases of benign intracerebral cysts is given. The average age of these patients is surprisingly high for a presumed congenital condition. There is a female preponderance, but the previously reported overrepresentation of left-sided lesions is not found in cases described after the introduction of computerized tomographic imaging.

Age Factors↗
PubMed1992

Gender distribution and sidedness of middle fossa arachnoid cysts: a review of cases diagnosed with computed imaging.

According to earlier reports, arachnoid cysts seem to occur more frequently in males, and on the left side. The latter phenomenon could, however, be explained by a greater significance attributed to symptoms from the dominant hemisphere as a justification for invasive procedures in the pre-computed tomography era. The literature from the last third of the era of computed tomography is reviewed with respect to gender distribution and sidedness for middle fossa arachnoid cysts. Also included are a few cases of our own from the same period. It is evident from this survey of the literature, based on computed tomography studies, that there is a significant tendency for these cysts to occur in males, with a male/female ratio of nearly 3:1. This preponderance toward males could not be explained by the somewhat higher frequency of associated subdural hematomas that was found in male patients. The survey also showed that middle fossa arachnoid cysts occur or are detected significantly more frequently on the left side than on the right, with a ratio of 1.8:1.

Arachnoid Cysts↗
PubMed1992

Dichotic listening studies of hemispheric asymmetry in brain damaged patients.

In the present paper we review the empirical evidence for structural versus attentional explanations of the right ear advantage (REA) phenomenon in dichotic listening (DL). The ear advantage in DL is a behavioral "marker" of language function in the cerebral hemispheres. Dichotic listening data from four brain-lesioned patients are presented. The patients had a tumor or cyst in the left Sylvian region (2 cases); hemorrhage in the left frontotemporal region (1 case); and severe destruction of the left hemisphere (1 case). The results from all four patients showed marked reductions in correct recall of the right ear items, while left ear recall was left unaffected. In two of the cases, the DL data showed an immediate reinstatement of the REA after neurosurgery. It is concluded that the results favor a structural/anatomical explanation of the ear advantage phenomenon in DL, rather than an attentional bias explanation.

Adult↗
PubMed1991

Determination of DNA ploidy and ABH antigen reactivity in both frozen and formalin-fixed bladder tumor tissue.

In a prospective series of patients with transitional-cell bladder carcinomas, DNA ploidy and ABH antigen reactivity were determined in both frozen tissue and formalin-fixed paraffin blocks. ABH antigen measurement in frozen tissue was hampered by methodological problems, especially insufficient morphology, which made quantification difficult. In only 38/55 (69%) cases was the same ABH reactivity found. The knowledge of secretor status was not helpful in the interpretation of these results. In 53/59 (90%) cases the same DNA ploidy was achieved, resulting in good correlation between flow cytometric DNA measurements in formalin-fixed and frozen tissue. The deviations occurred mainly in cases exhibiting a tetraploid DNA profile. DNA assessments using image cytometry on imprints of fresh tissue was a rapid and reliable method in our hands, with identical results being obtained in 32/36 (89%) cases.

ABO Blood-Group System↗
PubMed1991

Auditory neglect after right frontal lobe and right pulvinar thalamic lesions.

Auditory unilateral neglect or extinction to simultaneous stimulation is reported in a right-handed male with a lesion in the right frontal lobe and in the right thalamic pulvinar area. The patient was submitted to stereotactic thalamotomy for a post-traumatic intentional ataxia in the left extremities. He was subjected to repeated tests with dichotic listening to consonant-vowel syllables under three different attentional instructions. He was also tested monaurally with the same stimulus materials as used in the dichotic test. The results showed almost complete extinction of the left ear input during dichotic presentations, despite normal hearing when tested with audiometer screening. The left ear extinction effect was independent of instructions to attend to the left or right ear input. However, during monaural presentation, correct left ear reports increased to about 85%. The results are interpreted as showing an auditory attentional neglect caused by the right frontal and pulvinar lesions.

Adult↗
PubMed1991

Distribution of tamoxifen and metabolites into brain tissue and brain metastases in breast cancer patients.

We determined the amount of tamoxifen, N-desmethyltamoxifen (metabolite X), N-desdimethyltamoxifen (metabolite Z), and hydroxylated metabolites (Y, B, BX) in brain metastases from breast cancer and in the surrounding brain tissues. Specimens were collected from the breast cancer patients who received tamoxifen for 7-180 days and with the last dose taken within 28 h before surgical removal of the tumour. The concentrations of tamoxifen and its metabolites were up to 46-fold higher in the brain metastatic tumour and brain tissue than in serum. Metabolite X was the most abundant species followed by tamoxifen and metabolite Z. Small but significant amounts of the hydroxylated metabolites, trans-1(4-beta-hydroxyethoxyphenyl)-1,2-diphenylbut-1-ene (metabolite Y), 4-hydroxytamoxifen (metabolite B) and 4-hydroxy-N-desmethyltamoxifen (metabolite BX) were detected in most specimens. The ratios between the concentrations of tamoxifen and various metabolites were similar in tumour, brain and serum. This is the first report on the distribution of tamoxifen and metabolites into human brain and brain tumour, and the data form a basis for further investigation into the therapeutic effects of tamoxifen on brain metastases from breast cancer.

Adult↗
PubMed1991

Dichotic listening during forced-attention in a patient with left hemispherectomy.

A young left-handed girl with an extensive posttraumatic lesion in the left hemisphere was tested with dichotic listening (DL) under three different attentional instructions. The major aim of the study was to evaluate a structural vs attentional explanation for dichotic listening. As both her expressive and receptive language functions were intact after the lesion, it was assumed that the right hemisphere was the language-dominant one. In the free-report condition, she was free to divert attention to and to report from both ear inputs. In the forced-right condition, she was instructed to attend to and report only from the right ear input. In the forced-left condition, she was instructed to attend to and to report only from the left-ear input. Her performance was compared with data from a previously collected sample of normal left-handed females. Analysis showed that the patient, in contrast to the normal sample, revealed a complete right-ear extinction phenomenon, irrespective of attentional instruction. Furthermore, she showed superior correct reports from the left ear, compared with those of the normal sample, also irrespective of attentional instruction. It is concluded that these results support a structural, rather than attentional explanation for the right-ear advantage (REA) typically observed in dichotic listening. The utility of validating the dichotic listening technique on patients with brain lesions is discussed.

Adolescent↗
PubMed1990

Interaction between human brain tumour biopsies and fetal rat brain tissue in vitro.

The invasiveness of human intracranial tumours was studied in an organ culture system. Biopsies from six glioblastomas, four astrocytomas, two mixed gliomas, one ependymoma, four meningiomas and two carcinoma metastases were cut into fragments of 0.5 mm diameter, and placed in agar overlay tissue culture. The tumour specimens formed spheroids which were co-cultured with cell aggregates or fragments from fetal rat brain for up to 10 days in vitro. The invasiveness of the glioblastoma spheroids was characterised by a gradual destruction of normal brain tissue by tumour cells, followed by replacement of normal tissue by these cells. Co-cultures from two glioblastomas showed lesions in the normal brain tissue in areas removed from the tumour cells. Tumour spheroids from four glioblastomas totally destroyed the normal brain tissue without any change in the original tumour spheroid configuration. The low-grade gliomas were less invasive than the glioblastomas. The meningiomas and the metastases were non-invasive. This organ culture assay appeared to reflect the in situ invasive behaviour of the brain tumours examined. It is suggested that it may be used for evaluating the aggressiveness of individual brain tumours with the specific aim of correlating clinical data with the biological character of the tumour.

Adolescent↗
PubMed1990

Dynamic aspects of expanding cava septi pellucidi et Vergae.

Two paediatric patients with expanding cysts of the cava Vergae et septi pellucidi are presented. In the first patient, consecutive CT scans showed a growing cavum thought to be responsible for his dramatic increase in head circumference. In the other patient, the expanding cavum was discovered because a routine skull X-ray after minor head trauma revealed marked impressiones digitatae. Both patients were successfully treated with stereotactically placed internal shunts from the cysts via the lateral ventricle to the subarachnoid space. During this procedure, contrast medium was instilled, and the cysts were visualized on postoperative CT scans. Some dynamic aspects of such expanding cava are discussed.

Brain Diseases↗
PubMed1990

The role of the left and right thalamus in language asymmetry: dichotic listening in Parkinson patients undergoing stereotactic thalamotomy.

Fourteen patients with Parkinson's disease (rigidity and unilateral tremor as main symptoms) were treated with stereotactic thalamotomy. The operation was performed in either the left or right ventrolateral thalamus, depending on which hand (or foot) was most affected with tremor. Nine patients were operated on the left side and four on the right side. All patients were tested for asymmetry of language functioning with dichotic presentations of consonant-vowel (CV) syllables. The patients had to indicate which of the two syllables he/she heard on each trial. Dichotic listening was performed before and after the operation, as well as during electrical stimulation of the VL nucleus just before the lesion was carried out. The results revealed essentially three things: an overall reduced right ear advantage (REA) in the patient group compared to what is known from studies of healthy individuals; an increase in REA during left-sided stimulations; and a marked reduction in REA after left-sided lesions. It is concluded that the present data support the notion put forward by Ojemann (e.g., 1975) of a lateralized activating gating mechanism in the left VL nucleus that gates access for language information to the appropriate cortical areas. The gating mechanism seems to be activated by stimulation, and deactivated after lesions. Dichotic listening may thus be a heuristic instrument in assessment of language functions in Parkinson patients.

Adult↗
PubMed1990

Stereotaxic thalamotomy--experiences from the levodopa era.

After the introduction of levodopa drugs in the late 1960s, the number of thalamotomies fell dramatically world wide. However, as the Parkinsonian tremor proved rather resistant to levodopa treatment, the interest in this operation has been reviewed. During 1978-86, 51 stereotaxic thalamotomies were performed in 48 patient in our department. Thirty three of these patients had Parkinsonism, nine multiple sclerosis (MS) and the remaining six had various other involuntary movement disorders. The operation was most useful in the Parkinsonian group. Nearly 80% of these patients gained a substantial benefit in their daily lives. Patients with MS were all in advanced stages of the disease, and the operation was tried as a last resort. They had less benefit and more complications from operation than the other patients.

Aged↗
PubMed1990

Dichotic listening in an aphasic male patient after a subcortical hemorrhage in the left fronto-parietal region.

Dichotic listening (DL) performance to consonant-vowel (CV) syllables is reported in an aphasic right-handed male patient. The patient suffered initially from a complete expressive aphasia after an intracerebral hemorrhage caused by the rupture of an arteriovenous malformation (AVM) underlying Broca's area. The patient was tested three times with DL; one week after the hemorrhage, five weeks after, and after at about 6 months. At the first test he could not speak, but understood well. At the second test he uttered one-syllable words, and could answer "yes" and "no" to questions. At the third test he could speak whole sentences, although slow and "stutter-like." Dichotic listening performance showed an almost perfect match with speech recovery. At the first test he showed a left ear advantage which changed to no ear advantage at the second test, and to a right ear advantage at the third test. The overall performance was markedly reduced at the first test, but improved at the following test. It is concluded that dichotic listening may be a valid complement to traditional language assessment procedures after unilateral brain lesions.

Adult↗